Re: [time-nuts] FreeBSD version
In message , Josep h Gray writes: >I know this has been asked in the past, but things change and new >versions come out. So, what is the currently recommended version of >FreeBSD to use for an NTP server? Is the same version recommended for >a NanoBSD build? I'm probably going to build a server from a Net4501 >and another from an old "internet appliance" PC with a WinChip (sort >of a 586). Does that change the recommendations any? I would go with freebsd 7 at this point. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] FreeBSD version
I know this has been asked in the past, but things change and new versions come out. So, what is the currently recommended version of FreeBSD to use for an NTP server? Is the same version recommended for a NanoBSD build? I'm probably going to build a server from a Net4501 and another from an old "internet appliance" PC with a WinChip (sort of a 586). Does that change the recommendations any? Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS - fluke.l
My apolgies. In Arial font upper case I is graphically identical to lower case l. Aargh! John K1AE - Original Message - From: "Robert Darlington" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 4:50 PM Subject: Re: [time-nuts] GPS with PPS No, it's fluke.L (well, lowercase L), not upper case i. -Bob On Wed, Sep 30, 2009 at 2:45 PM, John Allen wrote: Hello All - The seller's eBay ID is fluke.I. The uppercase letter. Back to our regular fine Programming, John K1AE - Original Message - From: "Roy Phillips" > To: "Discussion of precise time and frequency measurement" < time-nuts@febo.com> Sent: Wednesday, September 30, 2009 6:46 AM Subject: Re: [time-nuts] GPS with PPS Joe I would suggest that you could consider one of the Garmin GPS 16/17 models, that have been offered by Fluke1(China) at a sensible price. I have a GPS 16HVS which is performing very well just sitting on a window-sill (facing North), this offers a 1pps timing signal. It requires between 8.0 to 40 volts D.C (nominally 12.00 volts @ 40 mA. The alternative model, 16LVS, requires 3.3 to 8.0 volts.D.C @ 65 mA. All the data on these devices is available on the Garmin website Good luck Roy - Original Message - From: "Joseph Gray" To: "Discussion of precise time and frequency measurement" < time-nuts@febo.com> Sent: Wednesday, September 30, 2009 9:36 AM Subject: [time-nuts] GPS with PPS Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. Thanks, Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Joe, Joseph Gray wrote: Magnus, Thanks for the explaination. I forgot about ionispheric latency effects. I'll look for the book you mentioned. I think there is two books one should get: Elliot D. Kaplan & Christopher J. Hegarty, "Understanding GPS; Principles and Applications; Second edition", Artech House, ISBN 1-58053-894-0. This book covers the field in such a way that you get a good feel for it. It covers sufficiently many details such that you with that book and the ICD-GPS-200 can actually implement a receiver. Pratap Misra & Per Enge, "Global Positioning System; Signals, Measurements, and Performance; Second Edition", Ganga-Jamuna Press, ISBN 0-9709544-1-7. This book is better at concepts, details and certain in-depths of the more advanced fields. The exercises at the end of each chapter makes it better adapted for a coarse. This complements the Kaplan&Hegarty in the theoretical field and issues relating to precission tracking. As an example in the difference of approaches. While Misra&Enge provides details analysis of tracking properties of a typical DLL layout, Kaplan%Hegarty provides a good overview of topologies, their properties and also cook-book like formulas for how to parameterize FLL and PLL loops. Thus, the Kaplan&Hegarty is more practical while Misra&Enge is more theoretical. I just happend to see both approaches as sound. The recent discussion on teoretical limits for a MPS takes not that much space in Kaplan&Hegarty to describe the concepts and calculations while Misra&Enge devotes Chapter 10 to the topic. The antenna pattern view in Kaplan%Hegarty is missing in the Misra&Enge, even if they attempt to say the same thing. Hmm... the antenna plot is in the old Kaplan book, which I also have. Anyway, the plot of gain vs. elevation is still there. However, if you want to really understand the field, a couple of more books should be on the bookshelf. But these should get most people where they want to be on understanding GPS and indeed other similar GNSS systems and their various augmentation variants. NavtechGPS.com should be a good source. They have a good selection of books. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Kaplan and Hegarty book
> > > > Dip your nose into the Kaplan & Hegarty book for instance. That is what I > > used to reinforce my recollection of things. There are better sources. http://www.amazon.com/Understanding-GPS-Principles-Applications-Second/dp/1580538940 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Magnus, Thanks for the explaination. I forgot about ionispheric latency effects. I'll look for the book you mentioned. Joe KA5ZEC On Wed, Sep 30, 2009 at 4:11 AM, Magnus Danielson wrote: > Dear Joe, > > Joseph Gray wrote: >> >> Does anyone know if any of those all-in-one hockey puck GPS receivers >> put out PPS on the serial cable? The type that has the antenna and GPS >> together, with a serial cable hanging off of it. I'm thinking about >> using one for a timing project. The more sensitive, the better, as it >> will be used indoors. >> >> While I'm on the subject of GPS units, a question comes to mind. I >> know that WAAS enhances position accuracy. Does it do anything for >> time? My first thought would be no, as that comes directly from the >> standard GPS satellites. > > It does. It improves the GPS position in [XYZT]. However, it does not work > its magic in a direct sense to time itself. The fast corrections adjust the > pseudo-range measures comming out the channels. Ionspheric errors is also > corrected by transmitting grid-based data and the receiver interpolates the > correction value for its (coarse) location and make individual corrections. > SBAS (WAAS is one of several SBAS systems) also corrects for satellite orbit > parameters, and UTC offsets. > > These corrections all aids to improve the GPS position in [XYZT] where the > improvement in T is for most users a side-effect. A GPS with fixed position > can (if the receiver supports time-only mode) get a quicker and more > accurate fix (modulus local multipath) and then produce more accurate time > value as the SBAS aiding reduces the biasing errors and fluctuations of > those. Using a LBAS broadcast could improve the state further. > > Dip your nose into the Kaplan & Hegarty book for instance. That is what I > used to reinforce my recollection of things. There are better sources. > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Well, fluke currently only has the GPS16 HVS. The least expensive GPS18x LVC I've found so far (on or off ebay) is here: http://cgi.ebay.com/NEW-Garmin-GPS-18x-LVC-Receiver-010-00321-36_W0QQitemZ400075170888QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item5d2656a448&_trksid=p3286.c0.m14 Thanks to all for the input. Joe Gray KA5ZEC On Wed, Sep 30, 2009 at 4:05 PM, Robert Darlington wrote: > http://myworld.ebay.com/fluke.l/ > > > > On Wed, Sep 30, 2009 at 2:59 PM, Dave hartzell wrote: > >> Can someone provide a link? I can't seem to find it... >> >> On Wed, Sep 30, 2009 at 1:50 PM, Robert Darlington > >wrote: >> >> > No, it's fluke.L (well, lowercase L), not upper case i. >> > >> > >> > -Bob >> > >> > On Wed, Sep 30, 2009 at 2:45 PM, John Allen > > >wrote: >> > >> > > Hello All - >> > > >> > > The seller's eBay ID is fluke.I. The uppercase letter. >> > > >> > >> ___ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
http://myworld.ebay.com/fluke.l/ On Wed, Sep 30, 2009 at 2:59 PM, Dave hartzell wrote: > Can someone provide a link? I can't seem to find it... > > On Wed, Sep 30, 2009 at 1:50 PM, Robert Darlington >wrote: > > > No, it's fluke.L (well, lowercase L), not upper case i. > > > > > > -Bob > > > > On Wed, Sep 30, 2009 at 2:45 PM, John Allen > >wrote: > > > > > Hello All - > > > > > > The seller's eBay ID is fluke.I. The uppercase letter. > > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] VLF time stations in Europe
In message <00d701ca4212$e2a41890$0900a...@lark>, "Alan Melia" writes: >Possibly the local noise is the >problem though the signal is quite strong. I maybe didnt give it long >enough.well its French :-)) I built this active antenna last year, and it is the best I have had yet, I have been able to pull in signals fram 9kHz to 200MHz with it, highly recommended: http://www.home.earthlink.net/~christrask/Paper007.html Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] VLF time stations in Europe
Ah thanks for that Poul I knew there was some data on it which averages out but was not sure what it was. I have a source locked to Droitwich here (which doesnt have time-code), but I have never had a successful lock to Allouis (an option on my off-air unit) Possibly the local noise is the problem though the signal is quite strong. I maybe didnt give it long enough.well its French :-)) Alan G3NYK - Original Message - From: "Poul-Henning Kamp" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 8:44 PM Subject: Re: [time-nuts] VLF time stations in Europe > In message <00b501ca4205$69611440$0900a...@lark>, "Alan Melia" writes: > > >Hi Magnus TDF (?) France Inter ( Allouis ) is, I believe, a strictly > >frequency distribution station [...] > > They send DCF77 like timecode with phase-shifts. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Can someone provide a link? I can't seem to find it... On Wed, Sep 30, 2009 at 1:50 PM, Robert Darlington wrote: > No, it's fluke.L (well, lowercase L), not upper case i. > > > -Bob > > On Wed, Sep 30, 2009 at 2:45 PM, John Allen >wrote: > > > Hello All - > > > > The seller's eBay ID is fluke.I. The uppercase letter. > > > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
No, it's fluke.L (well, lowercase L), not upper case i. -Bob On Wed, Sep 30, 2009 at 2:45 PM, John Allen wrote: > Hello All - > > The seller's eBay ID is fluke.I. The uppercase letter. > > Back to our regular fine Programming, John K1AE > > - Original Message - From: "Roy Phillips" > > To: "Discussion of precise time and frequency measurement" < > time-nuts@febo.com> > Sent: Wednesday, September 30, 2009 6:46 AM > Subject: Re: [time-nuts] GPS with PPS > > > > Joe >> I would suggest that you could consider one of the Garmin GPS 16/17 >> models, that have been offered by Fluke1(China) at a sensible price. I have >> a GPS 16HVS which is performing very well just sitting on a window-sill >> (facing North), this offers a 1pps timing signal. It requires between 8.0 to >> 40 volts D.C (nominally 12.00 volts @ 40 mA. The alternative model, 16LVS, >> requires 3.3 to 8.0 volts.D.C @ 65 mA. All the data on these devices is >> available on the Garmin website >> Good luck >> Roy >> >> - Original Message - From: "Joseph Gray" >> To: "Discussion of precise time and frequency measurement" < >> time-nuts@febo.com> >> Sent: Wednesday, September 30, 2009 9:36 AM >> Subject: [time-nuts] GPS with PPS >> >> >> Does anyone know if any of those all-in-one hockey puck GPS receivers >>> put out PPS on the serial cable? The type that has the antenna and GPS >>> together, with a serial cable hanging off of it. I'm thinking about >>> using one for a timing project. The more sensitive, the better, as it >>> will be used indoors. >>> >>> While I'm on the subject of GPS units, a question comes to mind. I >>> know that WAAS enhances position accuracy. Does it do anything for >>> time? My first thought would be no, as that comes directly from the >>> standard GPS satellites. >>> >>> Thanks, >>> >>> Joe Gray >>> KA5ZEC >>> >> > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Hello All - The seller's eBay ID is fluke.I. The uppercase letter. Back to our regular fine Programming, John K1AE - Original Message - From: "Roy Phillips" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 6:46 AM Subject: Re: [time-nuts] GPS with PPS Joe I would suggest that you could consider one of the Garmin GPS 16/17 models, that have been offered by Fluke1(China) at a sensible price. I have a GPS 16HVS which is performing very well just sitting on a window-sill (facing North), this offers a 1pps timing signal. It requires between 8.0 to 40 volts D.C (nominally 12.00 volts @ 40 mA. The alternative model, 16LVS, requires 3.3 to 8.0 volts.D.C @ 65 mA. All the data on these devices is available on the Garmin website Good luck Roy - Original Message - From: "Joseph Gray" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 9:36 AM Subject: [time-nuts] GPS with PPS Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. Thanks, Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] VLF time stations in Europe
In message <00b501ca4205$69611440$0900a...@lark>, "Alan Melia" writes: >Hi Magnus TDF (?) France Inter ( Allouis ) is, I believe, a strictly >frequency distribution station [...] They send DCF77 like timecode with phase-shifts. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] VLF time stations in Europe
In message <4ac3a6d5.9040...@rubidium.dyndns.org>, Magnus Danielson writes: >I am trying to make an overview of VLF time stations that can reach >Sweden and may be of practical use. There is a russian station at 200/3 kHz with timesignals, it's a bit too faint on my antenna to be usable. >I know of the Russian military Beta signal (20,5 kHz to 25,5 kHz) [...] Are you talking about the Omega clone in the 9-12 kHz range or some other transmitters ? In general most of the Russian stuff keeps lousy time, some of them wander off and only get adjusted twice a year etc. >I also know of Chayka, the Russian equalent of Loran-C. Considering to >include it. It's pretty tricky to get a good signal out of, because the GRI is 8000 which means that you cannot filter CW noise out by integration. See also: http://phk.freebsd.dk/AducLoran http://phk.freebsd.dk/loran-c/CW/ Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] VLF time stations in Europe
Hi Magnus TDF (?) France Inter ( Allouis ) is, I believe, a strictly frequency distribution station like Droitwich 198kHz (UK) carrier referenced to a rubidium and measured by the French national bureau I expect. Details of MSF and Droitwich are available from NPL http://www.npl.co.uk/science-technology/time-frequency/time/ MSF, HBG, and DCF77 transmit time code, whereas there is data on the MSF and Allois carriers it is not time-code. I think Droitwich carries a utility service a little like DCF39 Magdeburg but less wide ranging. I think Droitwich is 500kW but may reduce at night. Alan G3NYK - Original Message - From: "Magnus Danielson" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 7:43 PM Subject: [time-nuts] VLF time stations in Europe > Fellow time-nuts, > > I am trying to make an overview of VLF time stations that can reach > Sweden and may be of practical use. > > Loran-C at 100 kHz seems obvious. > > DCF77 at 77,5 kHz (50 kW in Germany) is known, certainly within range > (my receiver works without much trouble). > > MSF at 60 kHz (17 kW in GB) also works (a friend has working reception). > > TDF at 162 kHz (2 MW in France) should reach according to published > chart, 3500 km range includes all of Sweden. > > HBG at 75 kHz (25 kW in Switzerland) may be a little to faint to be > useable? 1000 km range seems too short. To close down in 2011. > > I know of the Russian military Beta signal (20,5 kHz to 25,5 kHz), but > consider it of less importance in this case. Is received in Norway where > reverse-engineering has been done. > > I also know of Chayka, the Russian equalent of Loran-C. Considering to > include it. > > I assume that signal should be of considerable strength such that > regular use does not require DX-ing skills and that fairly regular use > can be made without having to figth wars agains S/N issues. > > Can anyone spot an obvious missing signal? > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] VLF time stations in Europe
Hi Magnus, The BBC's "Radio 4" signal on 198 KHz should be another contender. Beware that it has slow (25Hz?) phase mod that carries commercial data signals. From memory, the data packets are 50 bits each, so each spans 2 seconds. Time is sent leading up to the top of the minute, and other packet(s) are used by the Electricity industry to switch our domestic off-peak "Economy-7" storage heater systems on and off. But the service was never fully exploited or utilised, and so many packets just carry nulls. If you beat the signal with a local oscillator, then view a narrow band waterfall display on a spectrum analyser program, you can see a repeating pattern! Peter Vince (G8ZZR, London) On Wed Sep 30 20:43 , Magnus Danielson sent: >Fellow time-nuts, > >I am trying to make an overview of VLF time stations that can reach >Sweden and may be of practical use. > >Loran-C at 100 kHz seems obvious. > >DCF77 at 77,5 kHz (50 kW in Germany) is known, certainly within range >(my receiver works without much trouble). > >MSF at 60 kHz (17 kW in GB) also works (a friend has working reception). > >TDF at 162 kHz (2 MW in France) should reach according to published >chart, 3500 km range includes all of Sweden. > >HBG at 75 kHz (25 kW in Switzerland) may be a little to faint to be >useable? 1000 km range seems too short. To close down in 2011. > >I know of the Russian military Beta signal (20,5 kHz to 25,5 kHz), but >consider it of less importance in this case. Is received in Norway where >reverse-engineering has been done. > >I also know of Chayka, the Russian equalent of Loran-C. Considering to >include it. > >I assume that signal should be of considerable strength such that >regular use does not require DX-ing skills and that fairly regular use >can be made without having to figth wars agains S/N issues. > >Can anyone spot an obvious missing signal? > >Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] VLF time stations in Europe
Fellow time-nuts, I am trying to make an overview of VLF time stations that can reach Sweden and may be of practical use. Loran-C at 100 kHz seems obvious. DCF77 at 77,5 kHz (50 kW in Germany) is known, certainly within range (my receiver works without much trouble). MSF at 60 kHz (17 kW in GB) also works (a friend has working reception). TDF at 162 kHz (2 MW in France) should reach according to published chart, 3500 km range includes all of Sweden. HBG at 75 kHz (25 kW in Switzerland) may be a little to faint to be useable? 1000 km range seems too short. To close down in 2011. I know of the Russian military Beta signal (20,5 kHz to 25,5 kHz), but consider it of less importance in this case. Is received in Norway where reverse-engineering has been done. I also know of Chayka, the Russian equalent of Loran-C. Considering to include it. I assume that signal should be of considerable strength such that regular use does not require DX-ing skills and that fairly regular use can be made without having to figth wars agains S/N issues. Can anyone spot an obvious missing signal? Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
> Does anyone know if any of those all-in-one hockey puck GPS receivers > put out PPS on the serial cable? The type that has the antenna and GPS > together, with a serial cable hanging off of it. I'm thinking about > using one for a timing project. The more sensitive, the better, as it > will be used indoors. The Garmin GPS 18 is popular with the NTP crowd. A year or two ago it was replaced/upgraded with the 18x. There are 3 versions. One for USB (no PPS), one with bare wires (needs 5V and has PPS), and another with a car adapter. Be sure to get the right one. Mine is inside. It works most of the time. I've seen it report time that is off by a second. I think that only happens when it is recovering from not-enough-satellites, but I don't have good data. If you want another option, the best alternative I have seen is the GlobalSat MR-350. It's a through-hole mount rather than a magnetic mount. It comes with a PS-2 style connector. (You can chop it off.) The PPS is only 1 microsecond wide. -- These are my opinions, not necessarily my employer's. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Specifically the GPS 18x LVC (high-sensitivity, bare wires). David At 12:07 PM 9/30/2009, you wrote: The Garmin GPS-18 series with serial output (not USB) is a hockey puck with WAAS and PPS output. David At 06:46 AM 9/30/2009, you wrote: Joe I would suggest that you could consider one of the Garmin GPS 16/17 models, that have been offered by Fluke1(China) at a sensible price. I have a GPS 16HVS which is performing very well just sitting on a window-sill (facing North), this offers a 1pps timing signal. It requires between 8.0 to 40 volts D.C (nominally 12.00 volts @ 40 mA. The alternative model, 16LVS, requires 3.3 to 8.0 volts.D.C @ 65 mA. All the data on these devices is available on the Garmin website Good luck Roy - Original Message - From: "Joseph Gray" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 9:36 AM Subject: [time-nuts] GPS with PPS Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. Thanks, Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Stanford Research SR620 Measurement Bias
Hi Jürg, Jürg Kögel wrote: Make the adjustment in the correct sequence: 1. Set the Cal jumper to Cal Enable 2. Connect the reference to Ext Ref (rear) and Input A 3. Switch the counter to Ext Ref 4. Set the CalByte 50 for the best display (this is a very fine adjustement) 5. Switch the counter to Int Ref 6. Set the CalByte 4 for the best display (this adjustement is coarse, optimize!) 7. Set the Cal jumper to Cal Disable After this calibration my SR620 is with the external reference +/- 3 counts (9'999'999.9997x10'000'000,0003) previous value -210 counts with the internal reference +/- 6 counts previous value -25 counts Thanks for that clarification. It seems very reasnoble. I obviously never bothered to do a carefull calibration of my SR620, so I haven't picked up the fine grain details involved with these procedures. This is a good reminder that I should pay attention to those details. I think I can say the same for most of my gear. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
The Garmin GPS-18 series with serial output (not USB) is a hockey puck with WAAS and PPS output. David At 06:46 AM 9/30/2009, you wrote: Joe I would suggest that you could consider one of the Garmin GPS 16/17 models, that have been offered by Fluke1(China) at a sensible price. I have a GPS 16HVS which is performing very well just sitting on a window-sill (facing North), this offers a 1pps timing signal. It requires between 8.0 to 40 volts D.C (nominally 12.00 volts @ 40 mA. The alternative model, 16LVS, requires 3.3 to 8.0 volts.D.C @ 65 mA. All the data on these devices is available on the Garmin website Good luck Roy - Original Message - From: "Joseph Gray" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 9:36 AM Subject: [time-nuts] GPS with PPS Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. Thanks, Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Stanford Research SR620 Measurement Bias
Make the adjustment in the correct sequence: 1. Set the Cal jumper to Cal Enable 2. Connect the reference to Ext Ref (rear) and Input A 3. Switch the counter to Ext Ref 4. Set the CalByte 50 for the best display (this is a very fine adjustement) 5. Switch the counter to Int Ref 6. Set the CalByte 4 for the best display (this adjustement is coarse, optimize!) 7. Set the Cal jumper to Cal Disable After this calibration my SR620 is with the external reference +/- 3 counts (9'999'999.9997x10'000'000,0003) previous value -210 counts with the internal reference +/- 6 counts previous value -25 counts Best regards Jürg Kögel 2009/9/28 Magnus Danielson : > Ulrich, > > Ulrich Bangert wrote: >> >> Stan, >> >> I believe I made it with calbyte 4 as described on page 71 of the manual. > > How does that explains the shift with time-base? > > I think it is the wrong way around for a time-bias like this. Tweaking the > time-base will maybe fix it for one of the time-bases, but not for the > others. > > I'm digging deeper into this, I want to know how to fix it if I see it on > mine. > > Cheers, > Magnus > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Joe I would suggest that you could consider one of the Garmin GPS 16/17 models, that have been offered by Fluke1(China) at a sensible price. I have a GPS 16HVS which is performing very well just sitting on a window-sill (facing North), this offers a 1pps timing signal. It requires between 8.0 to 40 volts D.C (nominally 12.00 volts @ 40 mA. The alternative model, 16LVS, requires 3.3 to 8.0 volts.D.C @ 65 mA. All the data on these devices is available on the Garmin website Good luck Roy - Original Message - From: "Joseph Gray" To: "Discussion of precise time and frequency measurement" Sent: Wednesday, September 30, 2009 9:36 AM Subject: [time-nuts] GPS with PPS Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. Thanks, Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS with PPS
Dear Joe, Joseph Gray wrote: Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. It does. It improves the GPS position in [XYZT]. However, it does not work its magic in a direct sense to time itself. The fast corrections adjust the pseudo-range measures comming out the channels. Ionspheric errors is also corrected by transmitting grid-based data and the receiver interpolates the correction value for its (coarse) location and make individual corrections. SBAS (WAAS is one of several SBAS systems) also corrects for satellite orbit parameters, and UTC offsets. These corrections all aids to improve the GPS position in [XYZT] where the improvement in T is for most users a side-effect. A GPS with fixed position can (if the receiver supports time-only mode) get a quicker and more accurate fix (modulus local multipath) and then produce more accurate time value as the SBAS aiding reduces the biasing errors and fluctuations of those. Using a LBAS broadcast could improve the state further. Dip your nose into the Kaplan & Hegarty book for instance. That is what I used to reinforce my recollection of things. There are better sources. Cheers, Magnus ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] GPS with PPS
Does anyone know if any of those all-in-one hockey puck GPS receivers put out PPS on the serial cable? The type that has the antenna and GPS together, with a serial cable hanging off of it. I'm thinking about using one for a timing project. The more sensitive, the better, as it will be used indoors. While I'm on the subject of GPS units, a question comes to mind. I know that WAAS enhances position accuracy. Does it do anything for time? My first thought would be no, as that comes directly from the standard GPS satellites. Thanks, Joe Gray KA5ZEC ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
